Thermostatically controlled expansion valve



Oct. 24, 1933. Q 5 17: 1,932,356

THERMOSTATICALLY CONTROLLED EXPANSION VALVE File d Jan. 16, 1931 2 Sheets-Sheet l INVENTOR Dem C. Seiiz ATTORNEYS Oct. 24, 1933. a D. c, SEITZ 1,932,356

THERMOS'I'AT I CALLY CONTROLLED EXPANS ON VALVE v Filed Jan. 16, 1951 2 Sheets-Sheet 2 15 16 I :z-llla/l/l' ATTORNEYfi Dean L". Sez' tz v Patented Oct. 24, 1 933 UNITED STATES PArENr o Fw THERMOSTATICALLY ooN'raoLLEn- EXPANSION VALVE Dean 0. Seitzy Cleveland, Ohio, assignor to The Russ Manufacturing Company,

Cleveland,

I Ohio, a corporation of Ohio Application January 16, 1931.- Serial No. 509,100

5 Claims. (01. 62-8) This invention relates to refrigerating apparatus, and more particularly to expansion valve mechanism therefor.

One of the objects of the present invention is to provide an expansion valve of new and improved construction for controlling the amount of liquid refrigerant passing through a refrigerating' system.

Another object is to provide an expansion valve for refrigerating systems which is thermally controlled from some medium other than the refrigerant passing therethrough.

Another object is toprovide an expansion valve which is thermally controlled from a ,inedium other than the refrigeratirm medium under norof failure of certain parts is contiolled from the refrigerating medium.

A further object is to provide an expansion valve for controlling the amount of liquid refrigerant flowing through a refrigerating system embodying a valve actuating compartment hold ing a thermal medium other than the refrigerant which, through an increase or decrease in the vapor pressure thereof, actuates the expansion valve, and a compartment surrounding the first mentioned compartment through which the refrigerant being returned to the compressor passes. 7 Another object is to provide an expansion valve mechanism for refrigerating units in which the operation of the valve is unafiected by back pressure within the expansion chamber.

With the above and other objects in view which will be apparent from the following detailed description, this invention consists in certain features of construction and combinations of parts to be hereinafter claimed, that will be readily understood by those skilled in the art to which the invention appertains.

In the drawings which illustrate a suitable embodiment of the invention, 1

Figure 1 is a diagrammatic view of one type of refrigerating system having the expansion valves of my invention incorporated therein;

Fig. 2 is a partial enlarged longitudinal section of the expansion valve for controlling the flow of liquid refrigerant taken substantially on the line 2-2 of Fig. 4;

. Fig. 3 isa section taken on Fig. 4; and' Fig. 4 is a complete longitudinal section of the expansion valve device. I a

Referring to the accompanying drawings in which like numerals refer to like parts throughout the several views, the expansion valve mechtne line 3-3 of I be used equally as well in connection equipment such, for example, as electric houseanism of the present invention is shown incorporated with a diagrammatically illustrated refrigerating apparatus of the type suitable for use in soda fountain equipment. In this apparatus, the refrigerating medium compressed by the compressor 1 is first discharged through pipe la into a suitable condenser lb, diagrammatically illustrated in Fig. l as being of the water cooled type, and then circulated to the expansion valve device through the conduit 2 and from the ex pansion valve device the refrigerating medium then ,passes through the conduit 2d to a cooling coil 3 which may be submerged in a water bath or a bath of non-freezing solution disposed in the syrup jar rack 4. The purpose of the coil 3 is to maintain the interior of the syrup jar rack d at a desired temperature. From the cooling coil 3, the refrigerating medium passes back through a suction conduit 5 to the operating mechanism for the expansion valve and then through the conduit 5a to the compressor 1. A thermostat device is arranged to control the expansion valve in order to regulate the quantity of refrigerating medium supplied to the cooling coil 3 whereby the proper temperature may be maintained in the syrupjar rack. V v

, This system is what is commonly called a dry type system. The valve device of the present invention is especially adaptable for combining a dry and a flooded type system. .The valve is incorporated in the dry type system and the flooded type system which is diagrammatically represented by the evaporatorG is connected by a liquid conduit 2b with the liquid line 2 and by a suction conduit 5b to the suction line 5a that leads to the suction side of'the compressor 1. His thus possible by the use of the expansion valve of the present invention to, operate a dry type and a flooded type system from a single compressor.

Although theexpansion valveis shown in con-. nection with a'soda fountain refrigerating apparatus, it is to be understood that the same may with other hold refrigerators depending upon the formation of frost or ice around the cooling cpils for their cooling surface, or water coolers depending upon 1 the formation of ice around the expansion coil to effect the desired heat transfer between the water to be cooled and the intervening bath. In each of these installations the thermally operat- 'ed expansion valve to be hereinafter described would replace the expansion valve of the conventional unit. and the operation of this valve would be dependent upon the temperature of the cooled chamber or compartment.

The expansion valve of the present invention, as shown in Figs. 2 to 4-, inclusive, comprises an annular shell 7 disposed in the compressor liquid line, and having an inwardly extending rigid radial flange 8. A sleeve 10 is nested within the shell 7 to seat upon the radial flange 8 and to support an upper rigid radial flange 11 formed on an annular ring 12 that is preferably threaded into the upper end of the shell. "I. The shell 7 is formed with a projection 13 extending be tween the spaced flanges 8 and 11 which is formed with a fluid passage 13a and carries a suitable valve seat plug 1% threaded thereinto, coaxial with the shell 7.

i As shown in Fig. i, the sleeve 10 is formed with a recess 15 to permit the sleeve to be assembled over the projection 13 within the sleeve 7, and is formed with an opening 16 in alignment with the outlet opening 17 in the shell 7 that communicates with the liquid line 2a.

Each of the flanges is provided with a central opening 9, and one end of a bellows member 18 is secured to the metal defining the opening in the flange 8, and a bellows member 19 is secured to the metal defining the opening in the upper flange 11. The bellows members 18 and 19 extend in opposite directions coaxial with the shell 7 and the outer ends thereof are closed in with plates 20 and 21, respectively. Extending within the bellows members between the plates 20 and 21 is a yoke 22 which straddles the projection 13, the plates 20 and 21 being preferably threaded into the ends of the yoke to anchor the plates against relative movement.

The upper plate 21 carries a screw or metering pin 23 threaded therethrough which has a tapered end 24 that is adapted to cooperate with the valve seat and close the passageway 25 in the valve seat plug 14, thereby to regulate the flow or" refrigerant into the expansion chamber 26 provided between the flanges 3 and 11.

The ring 12, as shown in Fig. 4, is formed with a bridge member 27 extending diametrically across the same and having a central opening therein which threadably receives a cap screw 28. The cap screw 28 is coaxial with the valve seat plug 1 1 of the expansion valve and is provided with a central recess 29 which receives a compression spring 30, the spring 30 being arranged to seat against the upper bellows plate 21 and thereby hold the tapered end 24 of the screw 23 firmly against the tapered seat of the valve seat plug 14 in order to close the opening therein when it is desired to have no flow of liquid refrigerant.

The yoke 22 which is secured to the upper and lower plates 21 and 20, respectively, is arranged to be moved coaxially with the valve seat in order to move the valve screw 23 away from the valve seat plug 14 against the resistance of the spring 30 to thus regulate the flow of liquid refrigerant through the opening in the valve seat plug 14 into the expansion chamber 26. The flexible bellows members 18 and 19 carried by the plates 20 and 21 and secured to the flanges 8 and 11, respectively, move with the yoke 22 and thereby prevent the pressure in the expansion chamber 26 from, affecting the position of metering pin 23.

The opening and closing of the opening in the valve seat plug 14 in order to regulate the flow of refrigerant to the expansion chamber iscontrolled by thermostatic means which will now be described. Secured to the shell 7 coaxial thereoeaese with by means of suitable insulating rods 31 is an annular plate 32 having a central opening 33 therein which receives a rod 34 that is connected to the lower plate 20 carried by the bellows member 18. This rod 34 extends through the opening 33 in the annular plate 32 and is provided with a suitable head portion 35 preferably threaded thereon. One end of a bellows member 36 surrounding the actuating rod 3 3 is secured to the head 35 and the other end thereof is secured to the marginal edge of the annular plate 32. it. suitable cylindrical member 37 is preferably threaded onto the annular plate 32 to enclose the bellows member 36 and provide a chamber 33 therebetween. The other end of the cylindrical member 37 extends beyond the head 35 and is provided with a suitable closure 38a threaded thereinto, thus providing a sealed chamber 33 surrounding the bellows member 35.

it is obvious that any movement of the head 35 will cause the opening in the valve seat plug 14 to be opened or closed, as the case he, and that the valve unit will be actuated independently of the pressure of the fiuid contained wi'hin the expansion chamber so far as the position of the valve is concerned by reason of the fact that the expansion chamber 26 has a constant volume because the'two plates 20 and 21 are connected to the yoke 22 which prevents relative /movement therebetween.

Since the use of this valve in the present ap= plication is for the control of liquid refrigerant that is supplied to the cooling coil 3 in the syrup jar rack 4 of the soda fountain cabinet, it is desirable to control the valve with a temperature responsive device such as a bulb thermostat mounted in the syrup jar rack 44, the object being.

to have the control unit for the expansion valve respond to temperatures in the syrup jar rack.

A suitable thermostat of the bulb type is shown in the diagram as embodying a chambered bulb 39 filled with methyl chloride or other suitable highly volatile liquid that is in open communi cation wi'h the control chamber 38 surrounding the bellows 36 through a connecting conduit to which is preferably threaded into the closure 38a for the cylindrical member 37. The thermostat bulb 39 is disposed within the bath surrounding the coil 3.

In the operation of this arrangement an increase in temperature in the syrup jar rack will cause an increase in pressure of the medium within the bulb 39. This will be communicated to the control chamber 38 through the, conduit 40 and will act upon the head 35 by reason of the yielding walls of the bellows member 36.

The motion of the head 35 and rod 34 will be communicated to the yoke 22 to cause the valve screw 23 to move away from the valve seat 1% a predetermined distance, which movement is resisted by the spring 30. As a result of this movement, the valve stem is lifted from its seat a sufiicient degree to permit a flow of liquid refrigerant into the expansion chamber 26 and from there through the discharge openings 16 and 17 into the cooling coil 3 that is arranged in the solution carried by the syrup jar rack.

As the temperature in the syrup jar rack 4 is reduced, the thermostat bulb 39 mounted in the syrup jar rack is cooled, thus reducing the pressure of the methyl chloride or other medium in the bulb. This consequently reduces the pressure within the control chamber 38, which perl the suction conduit 5 leading from the coil 3 valve screw 23 toward its seat and throttle or completely shut off the flow of. liquid refrigerant into the expansion chamber 26.

In the present illus'ration where the bellows 36 is actuated by the direct contact of vapor from the temperature control bulb 39, it is desired to thermally insulate the chamber from the valve parts. This is accomplished by making the members 31 of bakelite or other suitable non-conductive material. i

In order to insure against the passage of excess refrigerant to the coil 3, I have provided means wherein the liquid refrigerant being conducted back to the compressor will cause the valve to beclosed. As shown in Figs. 3 and 4, the cylindrical member 37 is surrounded by a cylindrical shell 42 which seats against the annular plate 32 and against a suitable flange 43 formed on the closure The shell 42 is provided with in-, turned radial flanges 45 at its ends which seat" members 38a.

against the members 32 and 38a and is held in position by means of suitable bolts 46 extending through the members 32 and 38a and threaded into the insulating members 31. The cylindrical members 37 and 42 provide a closed annular chamber 4'7 and this chamber is connected into the suction side of the compressor unit 1. In the event that an excess of refrigerant is supplied to the coil 3, the reduced temperature of the refrigerant leaving the coil 3 and passing through the chamber 47 will cause a reduction of the vapor pressure in the chamber 38, which will then permit the expansion of the bellows unit 36 in response to the pressure of the spring 30 so that the tapered end 24 of the valve stem 23 will seat against the tapered opening of the valve seat plug 14 and thus prevent more liquid refrigerant from passing into the expansion chamber 26, until the excess has been evaporated and the temperature of the refrigerating medium in the chamber 4'?! rises to that of the bulb 39.

If the compartment to be cooled has been reduced to the desired temperature at which the expansion valve described above has closed the valve opening, permitting no more liquid refrigerant'to pass, the pressure in the expansion line will be rapidly reduced, permitting a' pressure control to be used in which great accuracy of setting is not required. In like manner the valve will open very rapidly with a rise in temperature in the compartment being cooled, and this in turn will immediately build up the pressure in the return line of the pump, thereby rendering sensitive control of the prime mover for the pump unnecessary, although relatively close thermal control is obtained in the compertinent being cooled.

0pc readily apparent advantage or the ex= pansion valve device dust described is that the back pressure within. the expansion chamber cannot aflect the quantity cf refrigerant passed into the expansion chamber through the valve.v

The operation of the valve is controlled solely by the expansion and contraction of the temperature responsive medium in the chamber 38 surrounding,

the bellows 3d. It is to be particularly noted that in the present invention an expansion valve is provided for controlling the amount of liquid refrigerant flowing through a refrigerating system,,which embodiesthe use oi a thermal medium other than the refrigerating medium. a

, Although I have shown the bellows members 18 and 19 for operating the valve, it is to be underher, and a I closed chamber, said closed chamber-and hollow.

such as diasented for purposes of explanation and illustration, and that various modifications of said apparatus can be made without departing from my invention as defined in the appended claims.

what I claim is: y 1. In an expansion valve device having an ex-' pansion valve for supplying refrigerant to a cooling device, means operated by the temperature of the cooling device for regulating the amount of refrigerant passing t ough said expansion valve, said means comprising a flexible member, means connecting said flexible member with said valve, a closed chamber adjacent said flexible member, and a hollow member connected for communication with said closed chamber, said closed volatile fluid sensitive to temperature changes, said hollow member being positioned near said cooling device whereby increase in temperature of said cooling device will increase the pressure of the fluid in said closed chamber and thereby cause said flexible member to open said expansion valve, and a second chamber surrounding said closed chamber for receiving refrigerant discharged from said cooling device whereby an excess of refrigerant supplied to said cooling device will enter said second chamber and decrease the pressure of the fluid in said closed chamber and allow said flexible member to return to normal position to thereby close or partially close said expansion valve. 1

2. An expansion valve device comprising an expansion chamber having inlet and outlet openings, a liquid passage leading within said chamber from said inlet opening and having a valve seat, a metering pin extending within said chamber and cooperating with said seat to regulate the flow of liquid into said chamber, and means positionedexternally of said chamber for moving said metering pin relative to said valve seat, comprising a bellows member, means connecting said bellows member with said metering pin, an en closed chamber surrounding said bellows memher, and a-chambered member containing a highly volatile temperature responsive fluid, said fluid being in communication with said chamber surrounding said bellows member whereby change in the pressure of said fluid causes said bellows member to actuate said metering pin.

3. In an expansion valve device having an exvalve, said means comprising an open flexible .chamber and hollow member containing a highly bellows member having a closed end, means rigidly connecting the closed end with said valve, a closed chamber surrounding said bellows memhollow member connected with said member containing a highly volatile fluid sensitive to, temperature changes, said hollow member being positioned near said cooling member whereby increase in temperature of said cooling member will increase the pressure of the fluid l neeaeee in said closed chamber and thereby cause said expansion valve to open, and a second chamber surrounding said closed chamber for receiving Hit) irigerant passage leading within said chamber from said inlet opening and having a valve seat, ametering pin extending within said chamber and cooperating with said seat to regulate the flow of liquid into said chamber, and means positionedexternally of said chamber for moving said metering pin-relative to said valveseat, said means comprising a closed chamber spaced from said expansion chamber, a fluid pressure actu ated element within-said closed chamber, means connecting said element with said metering pin,

and a chambered member containing a highly volatile temperature responsive fluid, said fluid being in counicationwith said closed chamber whereby change in the pressure of the fluid causes said element to actuate said metering pin.

5. An expansion valve device comprising an expansion chamber having an inlet opening and an outlet connected with a cooling member, a refrigerant passage leading within said chamber from said inlet opening and having a valve seat, a metering pin extending within said chamber and cooperating withpsaid seat to regulate the flow of liquid into said chamber, and means positioned externally of said chamber for moving said metering pin relative to said valve seat, said means comprising a closed chamber spaced from said expansion chamber, a fluid pressure actuated'element within said closed chamber, means connecting said element with said metering pin, and a chambered member containing a highly volatile temperature responsive fluid, said fluid being in communication with said closed chamber whereby change in the pressure of the fluid causes said element to actuate said metering pin,

said valve device also including a third chamber substantially surrounding said closed chamber for receiving refrigerant discharged from said cooling member whereby said' refrigerant in the event of an excess supply to said cooling member will decrease the pressure in said closed chamber, and allow said fluid pressure. actuated element to actuate said metering pin. a

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